There are known hanging-cable roof structures which have, an outer stiff ring and an inner stiff ring at different levels, between which there are stretched two systems of cables. One cable system is formed of intersecting cables which are chords of the outer stiff ring and touch tangentially the inner ring, while the other cable system is disposed over the first and is formed by cables extending radially between both contours.
A drawback for this known structure lies in the need of an internal stiff ring, supported at a given level over the ground by means of a special structure, which leads to the necessity of equipment and materials for its erection and to the occupation of useful space inside the building.
The roof structure is then erected necessarily with a scaffold and a number of erection devices.